Deposition of Functionally Graded Material Fabricated by Robot Plasma Arc Welding

Abstract

Functionally graded materials is a new type of composite materials capable of facilitating the dependable bonding of dissimilar materials. A double‐wire plasma welding process is used to manufacture SS316L/Inconel625 FGM. Subsequently, two thin‐walled structures with 5% gradient and non‐gradient are fabricated to investigate the morphology, microstructure, and properties in different gradients, focusing on the 67% SS316L region. The findings indicate that two depositions exhibit well‐formed structures with varying gradients and no macroscopic defects. The composition experiences an abrupt transition at the interface between deposition with a non‐gradient, whereas deposition with a 5% gradient does not exhibit this issue and demonstrates a higher effective deposition rate. The analysis of the energy dispersive spectrum indicates the presence of Nb elements at the grain boundary in the 67% SS316L region, with no observed cracks. This suggests resistance to cracking and impediment to the segregation of Nb. Additionally, the hardness and tensile strength in various regions exhibit a gradual increase with a 5% gradient of Inconel625 content, while the tensile anisotropy is not noticeable. Consequently, the 5% gradient transition demonstrates a more favorable performance in comparison to the non‐gradient sample, resulting in the avoidance of the 75% SS316L region due to its poor performance.This article is protected by copyright. All rights reserved.